It is known that the clotting of human blood is a complicated process, involving a series of reactions mediated by 13 different factors. It also is well known that a cause of hemophilia is the inability of the afflicted individual to synthesize one of these factors, known variously as antihemophilic factor, AHF, AHG or Factor VIII, in amounts sufficient to support adequate clotting. About 40 percent of hemophiliacs have no ability to synthesize Factor VIII, while the others have diminished ability. Dried preparations of Factor VIII concentrate are sold commercially for administration to hemophiliacs for treatment of bleeding or in advance of surgery. The Factor VIII concentrate is obtained from plasma obtained from human donors, through the use of known techniques. At the time of use, the dried concentrate is dissolved is sterile water, and the resulting solution is administered intravenously.
The Factor VIII preparation is not pure Factor VIII. Rather, it is a Factor VIII-enriched fraction obtained from plasma and contains other components. It is highly desirable that the Factor VIII concentrate be as pure as possible, but further improvements in purity through modification of the procedure for isolating Factor VIII from plasma are not practically feasible due to the difficulty of separating plasma components.